At that time, only four people at Apple knew about the project.
Starting in 2005, Apple allowed two US government contractors to work in their offices to develop a special version of the iPod, but exactly what that iPod would do was a mystery, and remains so today, as recounted in this fascinating tale by former iPod engineer David Scheier, which you should read.
The story begins like a novel:
At the end of 2005 it was a gray day. I was sitting at my desk writing code for the next generation iPod. Without knocking, the director of iPod Software—my boss’s boss—suddenly walked in and closed the door behind him. He got down to business. “I have a special task for you. Your boss doesn’t know about it. You’ll help two engineers from the US Department of Energy build a custom iPod. Just tell me."
This first paragraph sets the tone for the whole story, which has a lot of interesting details that only add to the legendary myth of Apple’s secrecy. For example:
Only four people at Apple knew about this secret project. I’m the director of iPod Software, vice president of the iPod division, and senior vice president of hardware. None of us work for Apple anymore. There were no paper trails. All communication was in person.
As for what the engineers were actually working on, here’s how Scheier describes it:
They wanted to add some special hardware to the iPod and write the data from that special hardware to the iPod disc in a way that would not be detected. But it still had to look and work like a regular iPod.
Shyer says he didn’t know what this special iPod would be used for. But he suggested that they were "building something like a stealth Geiger counter" that DOE agents could use to discreetly record levels of radioactivity while making it appear to everyone else that they were using a regular iPod. For example, walking around the city, listening to your tunes, and at the same time recording evidence of radioactivity. They could scan for smuggled or stolen uranium or evidence of a dirty bomb program without any chance of the press or the public finding out.
It all sounded like something out of a spy movie, but former iPod chief Tony Fadell says it’s all real.